I really love these Great Crested Grebes - they really start looking fantastic about now - I must get out and find some near me.
You have a nice composition for the head shot but your image quality isn't quite there, I'm afraid. Hard to know exactly where you have gone wrong as you haven't given any details of your post-production routine.
I'm thinking maybe this is a pretty substantial crop - which is probably where things have started to go wrong. The reds in the orange feathers look a bit over saturated - maybe blown out and recovered - also some of the whites on the neck.
Probably best to go back to your original file and start over on this one.
Nice portrait. The quality is lacking some as far as details, and I think the image is a bit bright. The pose is good but I think I would like to see a looser crop, esp on the bottom and you could use a little extra top and left as well.
Thank you Alison, Gerald and Marina for your comments and advice on how to improve the image. Here is a re-post taking your suggestions into account. Gerald, this is not a big crop but almost the full frame cropped to square for composition. Many thanks.